This will answer all: http://www1.us.dell.com/content/learnmore/learnmore.aspx?c=us&l=en&ref=C FG&s=gen&~id=serverharddrives&~line=servers&~mode=popup&~series=pedge&~t ab=details Si and SC are single channel, Di and DC are dual channel. "e" models (PERC4e/Si) is PCI-Express. DC/SC have less RAm then Di/Si but have more external channels (DC has 2, Di has 1 and SC has 1 and Si has none) ________________________________ From: thin-bounce@xxxxxxxxxxxxx [mailto:thin-bounce@xxxxxxxxxxxxx] On Behalf Of Dogers Sent: Friday, October 21, 2005 11:11 AM To: Thin List Subject: [THIN] OTish - Dell PERC's Does anyone know what the difference between the PERC4/SC, PERC4/DC, PERC/Whatevers are? Or where I can find out? Dells website either doesn't know or just plain doesn't like me.. Andrew